/Engine/Source/Runtime/Core/Public/Serialization/CompactBinaryPackage.h
Add the attachment to this package, along with any references that can be resolved.
void AddAttachment ( const [FCbAttachment](API\Runtime\Core\Serialization\FCbAttachment) & Attachment, [FAttachmentResolver](API\Runtime\Core\Serialization\FCbPackage\FAttachmentResolver) Resolver )